1. Field of the Invention
The present invention relates to hand operated cleaning tools, commonly known as squeegees.
2. Description of the Prior Art
For many years, designers of squeegees have attempted to design a squeegee that reduces the likelihood of scratching the smooth and vulnerable surfaces they are designed to clean. Scratching of the surface may occur during maneuvering of the tool causing the metallic squeegee blade holding rail to contact the window surface or from the rubber squeegee blade wearing down or tearing after extended use and exposing the metal frame to the window surface. When the squeegee is used in such a condition on a glass window or other smooth scratch prone surface, the metal frame particularly at the opposite ends will rub along the surface of the glass often resulting in scratching or marring of the surface. Other scratching occurs when the end of the squeegee frame is accidently struck against or rubbed along a glass surface. In these situations, it is the ends of the squeegee from that is most likely to scratch the glass surface.
It has long been a practice in the industry to seek to minimize this risk of surface scratching by applying a finish to the frame rail ends during the manufacturing process. Typically, at the end of the manufacturing process, the opposite ends of the frame rail are carefully machined or polished to remove all sharp corners or burrs to provide smooth rounded surfaces. Such metal frames or holders are often found in the form shown in my U.S. Pat. No. 4,611,363. However, such processing is labor intensive rendering it an expensive procedure thus driving up the cost of the end product.
Other efforts to provide a squeegee rail which will not subject the window surface to marring has led to the proposal that the opposite ends of the cross rail of the squeegee be capped by rounded U-shaped clips and secured in position by threaded bolts and nuts inserted through transverse bores. A device of this type is shown in U.S. Pat. No. 1,918,611 to Oberti. The design is likely to prevent some scratching and marring but has distinct drawbacks. The metallic clips, in order to prevent scratching, must be carefully shaped and perhaps even ground to remove any sharp edges. The fastening of the end clip by a nut and bolt makes assembly and blade replacement difficult cumbersome and time consuming. Professional window cleaners, paid by piece rate, are likely to disfavor a design that requires them to tediously remove the clips every time they need to replace or adjust their a blade. Moreover, the metallic clips are still likely to cause some scratching of the window, particularly if the nut and bolt assembly is capable of contacting the glass surface.
Scrapers have been proposed which include plastic and metal frames and configured on the opposite ends of the cross member with axially projecting ears. A scraper of this type is shown in U.S. Pat. No. 3,540,071 to Jorgensen. The plastic close to the outer extremities is likely to reduce the scratching but has drawbacks to a professional cleaner likely to use a squeegee frequently. The plastic frames made of soft plastic are more bulky and cumbersome when compared to the sleeker more simple design of the metal squeegee frames. The bulkiness of the squeegee is important to window cleaning professionals who use the squeegee for many hours a day. Plastic squeegees are not likely to have the long service life demanded by professional window cleaners. Plastic frames often become brittle with extended use and are therefore in need of frequent replacement.